HOW: Begin laying face up on the floor. Roll back and forth, until you have enough momentum for you to deep squat. Make sure that you are balanced prior to dropping back onto your back. You can use momentum with your arms to help assist you into the deep squat position. The timing is key with performing this exercise.
FEEL: The most difficult part of this exercise is likely keeping the leg straight on the non-weightbearing leg. You will feel the muscles on the front of the thigh work to keep this leg from hitting the floor.